diff options
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc/link/link_detection.c')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/link/link_detection.c | 173 |
1 files changed, 172 insertions, 1 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/link/link_detection.c b/drivers/gpu/drm/amd/display/dc/link/link_detection.c index 85303167a553..6d31f4967f1a 100644 --- a/drivers/gpu/drm/amd/display/dc/link/link_detection.c +++ b/drivers/gpu/drm/amd/display/dc/link/link_detection.c @@ -270,6 +270,10 @@ static void read_scdc_caps(struct ddc_service *ddc_service, uint8_t slave_address = HDMI_SCDC_ADDRESS; uint8_t offset = HDMI_SCDC_MANUFACTURER_OUI; + if (ddc_service->link->local_sink && + !ddc_service->link->local_sink->edid_caps.scdc_present) + return; + link_query_ddc_data(ddc_service, slave_address, &offset, sizeof(offset), sink->scdc_caps.manufacturer_OUI.byte, sizeof(sink->scdc_caps.manufacturer_OUI.byte)); @@ -858,6 +862,94 @@ static void verify_link_capability(struct dc_link *link, struct dc_sink *sink, verify_link_capability_non_destructive(link); } +/** + * link_detect_evaluate_edid_header() - Evaluate if an EDID header is acceptable. + * + * Evaluates an 8-byte EDID header to check if it's good enough + * for the purpose of determining whether a display is connected + * without reading the full EDID. + * + * @edid_header: The first 8 bytes of the EDID read from DDC. + * + * Return: true if the header looks valid (>= 6 of 8 bytes match the + * expected 00/FF pattern), false otherwise. + */ +static bool link_detect_evaluate_edid_header(uint8_t edid_header[8]) +{ + int edid_header_score = 0; + int i; + + for (i = 0; i < 8; ++i) + edid_header_score += edid_header[i] == ((i == 0 || i == 7) ? 0x00 : 0xff); + + return edid_header_score >= 6; +} + +/** + * link_detect_ddc_probe() - Probe the DDC to see if a display is connected. + * + * Detect whether a display is connected to DDC without reading full EDID. + * Reads only the EDID header (the first 8 bytes of EDID) from DDC and + * evaluates whether that matches. + * + * @link: DC link whose DDC/I2C is probed for the EDID header. + * + * Return: true if the EDID header was read and passes validation, + * false otherwise. + */ +static bool link_detect_ddc_probe(struct dc_link *link) +{ + if (!link->ddc) + return false; + + uint8_t edid_header[8] = {0}; + bool ddc_probed = i2c_read(link->ddc, 0x50, edid_header, sizeof(edid_header)); + + if (!ddc_probed) + return false; + + if (!link_detect_evaluate_edid_header(edid_header)) + return false; + + return true; +} + +/** + * link_detect_dac_load_detect() - Performs DAC load detection. + * + * Load detection can be used to detect the presence of an + * analog display when we can't read DDC. This causes a visible + * visual glitch so it should be used sparingly. + * + * @link: DC link to test using the DAC load-detect path. + * + * Return: true if the VBIOS load-detect call reports OK, false + * otherwise. + */ +static bool link_detect_dac_load_detect(struct dc_link *link) +{ + struct dc_bios *bios = link->ctx->dc_bios; + struct link_encoder *link_enc = link->link_enc; + enum engine_id engine_id = link_enc->preferred_engine; + enum dal_device_type device_type = DEVICE_TYPE_CRT; + enum bp_result bp_result; + uint32_t enum_id; + + switch (engine_id) { + case ENGINE_ID_DACB: + enum_id = 2; + break; + case ENGINE_ID_DACA: + default: + engine_id = ENGINE_ID_DACA; + enum_id = 1; + break; + } + + bp_result = bios->funcs->dac_load_detection(bios, engine_id, device_type, enum_id); + return bp_result == BP_RESULT_OK; +} + /* * detect_link_and_local_sink() - Detect if a sink is attached to a given link * @@ -942,6 +1034,12 @@ static bool detect_link_and_local_sink(struct dc_link *link, break; } + case SIGNAL_TYPE_RGB: { + sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C; + sink_caps.signal = SIGNAL_TYPE_RGB; + break; + } + case SIGNAL_TYPE_LVDS: { sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C; sink_caps.signal = SIGNAL_TYPE_LVDS; @@ -1066,7 +1164,30 @@ static bool detect_link_and_local_sink(struct dc_link *link, DC_LOG_ERROR("Partial EDID valid, abandon invalid blocks.\n"); break; case EDID_NO_RESPONSE: + /* Analog connectors without EDID: + * - old monitor that actually doesn't have EDID + * - cheap DVI-A cable or adapter that doesn't connect DDC + */ + if (dc_connector_supports_analog(link->link_id.id)) { + /* If we didn't do DAC load detection yet, do it now + * to verify there really is a display connected. + */ + if (link->type != dc_connection_dac_load && + !link_detect_dac_load_detect(link)) { + if (prev_sink) + dc_sink_release(prev_sink); + link_disconnect_sink(link); + return false; + } + + DC_LOG_INFO("%s detected analog display without EDID\n", __func__); + link->type = dc_connection_dac_load; + sink->edid_caps.analog = true; + break; + } + DC_LOG_ERROR("No EDID read.\n"); + /* * Abort detection for non-DP connectors if we have * no EDID @@ -1133,14 +1254,23 @@ static bool detect_link_and_local_sink(struct dc_link *link, sink = prev_sink; prev_sink = NULL; } - query_hdcp_capability(sink->sink_signal, link); + + if (!sink->edid_caps.analog) + query_hdcp_capability(sink->sink_signal, link); } + /* DVI-I connector connected to analog display. */ + if ((link->link_id.id == CONNECTOR_ID_DUAL_LINK_DVII || + link->link_id.id == CONNECTOR_ID_SINGLE_LINK_DVII) && + sink->edid_caps.analog) + sink->sink_signal = SIGNAL_TYPE_RGB; + /* HDMI-DVI Dongle */ if (sink->sink_signal == SIGNAL_TYPE_HDMI_TYPE_A && !sink->edid_caps.edid_hdmi) sink->sink_signal = SIGNAL_TYPE_DVI_SINGLE_LINK; else if (dc_is_dvi_signal(sink->sink_signal) && + dc_is_dvi_signal(link->connector_signal) && aud_support->hdmi_audio_native && sink->edid_caps.edid_hdmi) sink->sink_signal = SIGNAL_TYPE_HDMI_TYPE_A; @@ -1232,6 +1362,36 @@ static bool detect_link_and_local_sink(struct dc_link *link, return true; } +/** + * link_detect_analog() - Determines if an analog sink is connected. + * + * @link: DC link to evaluate (must support analog signalling). + * @type: Updated with the detected connection type: + * dc_connection_single (analog via DDC), + * dc_connection_dac_load (via load-detect), + * or dc_connection_none. + * + * Return: true if detection completed. + */ +static bool link_detect_analog(struct dc_link *link, enum dc_connection_type *type) +{ + /* Don't care about connectors that don't support an analog signal. */ + ASSERT(dc_connector_supports_analog(link->link_id.id)); + + if (link_detect_ddc_probe(link)) { + *type = dc_connection_single; + return true; + } + + if (link_detect_dac_load_detect(link)) { + *type = dc_connection_dac_load; + return true; + } + + *type = dc_connection_none; + return true; +} + /* * link_detect_connection_type() - Determine if there is a sink connected * @@ -1248,6 +1408,17 @@ bool link_detect_connection_type(struct dc_link *link, enum dc_connection_type * return true; } + /* Ignore the HPD pin (if any) for analog connectors. + * Instead rely on DDC and DAC. + * + * - VGA connectors don't have any HPD at all. + * - Some DVI-A cables don't connect the HPD pin. + * - Some DVI-A cables pull up the HPD pin. + * (So it's high even when no display is connected.) + */ + if (dc_connector_supports_analog(link->link_id.id)) + return link_detect_analog(link, type); + if (link->connector_signal == SIGNAL_TYPE_EDP) { /*in case it is not on*/ if (!link->dc->config.edp_no_power_sequencing) |